A RELIABILITY IMPROVEMENT PROPOSAL (RIP) MODEL FOR RELIABILITY ASSESSMENT OF ELECTRICAL DISTRIBUTION SYSTEMS

G.A. Ajenikoko

Department of Electronic & Electrical Engineering

Ladoke Akintola University of Technology, Ogbomoso

E-mail: ajeedollar@gmail.com

ABSTRACT

In Nigeria, the average interruptions that customers experience are very high and the degree varies from place to place, thus making it impossible to achieve a satisfactory degree of reliability in the power system. The need for an effective planning tool to evaluate alternative reliability improvement proposal in order to establish and prioritize reliability improvement recommendations for optimization of reliability performance of a power delivery system has necessitated the development of a Reliability Improvement Proposal (RIP) model. The model uses quantitative processes to optimize reliability performance expectations of both customers and regulatory authorities. This research paper focuses on a Reliability Improvement Proposal (RIP) model for reliability assessment of electrical power distribution systems. Seven major distribution systems-Ibadan, Ikeja, Ilorin, Port Harcourt, Kano, Kaduna and Benin were used as case studies. The development of the model started with identification and computation of major system reliability indices before and after the proposal. The changes in the system reliability indices and the weighting coefficients were then estimated using appropriate mathematical relations. The weighting coefficients show the extent to which the system reliability indices change when a RIP is suggested. The results of the RIP model showed that the system reliability indices has changed from 0.3433, 0.1198, 0.2291, 0.2629, 0.2352, 0.1964 and 0.0.4032 before the proposal to  0.9772, 0.9855, 0.9863, 0.9858, 0.9905, 0.9860 and 0.9793 after the proposal for Ibadan, Ilorin, Ikeja, Port Harcourt, Kaduna, Kano and Benin distribution systems respectively. The highest CAIDI weighting coefficient of 5.158 was recorded on Kano distribution system while the least SAIFI weighting coefficient of 0.0009214 was recorded on Ibadan distribution system as a result of the level of industrial activities of the city.  Kano distribution system has the least RIP value of -5.589 while Kano distribution system has the highest RIP value of 8.87 because of the level of power requirement of the city compared to any city in the case study.The results of this research paper will assist electrical power system engineers in making effective planning policies and prioritize reliability improvement recommendations so as to optimize reliability performance of electrical power system. 

MEASUREMENT OF RADIATION EXPOSURE TO PATIENTS DURING CHEST X-RAYS EXAMINATIONS AT LAUTECH TEACHING HOSPITAL, OSOGBO, SOUTH-WEST, NIGERIA.

¹Ajayi J.O, ¹Adedokun O. and ²Olabisi O

¹Department of Pure and Applied Physics

²Department of Science Laboratory Technology

 Ladoke Akintola University of Technology, Ogbomoso, Nigeria.

E-mail: simpleajayi@yahoo.com

ABSTRACT

Radiation doses received by patients during chest x-ray examinations were measured at the LadokeAkintola University of Technology Teaching Hospital, Osogbo on two different machines. Absorbed doses from full-size radiography were found to be within the acceptable limits for the posterior-anterior (P.A) view in adult and in children. The KV range for the two categories of patients, i.e. the adult and older children were recorded on the two generator types used, i.e. Phillips and Neo Diagnomax. The mean skin-entry doses of the patients x-rayed on the two generator types were obtained to be 64.18mrad and 61.46mrad for adult and children respectively on Philips generator, and 65.08mrad and 61.20mrad for adult and children respectively on Neo-Diagnomax.

LOOFAH (LUFFA CYLINDRICA, L.) BIODIESEL AS FUEL FOR DIESEL ENGINE

O.O. Oniya^a,*, A.I. Bamgboye^b

^aDepartment of Agricultural Engineering, Ladoke Akintola University of Technology, Ogbomoso ^bDepartment of Agricultural Engineering, University of Ibadan, Ibadan, Nigeria

E-mail: toyinprayer@yahoo.com

ABSTRACT

This study focussed on biofuel properties of biodiesel from loofah oil. Loofah oil was transesterified in a two-step transesterification process to produce ethyl-esters and glycerol. Biofuel properties of ethyl-esters were determined using ASTM Standards and compared with that of Automotive Gas Oil (AGO). Ethyl-ester yield of 80.0% was obtained from loofahoil. Same specific gravity of 0.88 was obtained for raw loofah oil and its ethyl ester was 1.023 times that of AGO. Higher viscosity at 40ºC (25mm²/s and 43.4mm²/s) was obtained for loofah ethyl ester and raw loofah oil respectively compared to 2.95 mm²/s obtained for AGO. Lower heating value (28.75 MJ/l) was obtained for loofah ethyl-ester compared to 30.2 MJ/l and 44.68 MJ/l obtained for raw loofah oil and AGO respectively. Lower amounts of sulphur, 9.13% for loofah ethyl ester and 10.41% for raw loofah oil than the reference AGO which was 61.8% were recorded. Higher pour (3ºC for both biofuels), cloud (7ºC and 8ºC) and flash (86ºC and 79ºC) points were obtained for loofah ethyl ester and the raw oil, respectively, compared to -16ºC, -12ºC and 74ºC respectively obtained for AGO. Loofah oil contained 76.46% of unsaturated fatty acids. Loofah ethyl ester had better fuel quality than raw loofah oil and fuel properties which are close to ASTM standards for diesel engine fuels.

Table of Contents

Application of Project Management Techniques in a Construction Firm

A. O. Odior.……………………………………………………………………………………………             1-7

Design, Construction and Evaluation of a Small Scale Solar Dryer

Onigbogi I.O, Sobowale, S. Sand Ezekoma, O.S……………………………………….                8-21

Road Pavement Failure Induced By Poor Soil Properties along Gombi-Biu

Highway, Nigeria

Hijab Mahmoud,  Zaynab A.  Belel  and Hadi  A.  Abba…….………………                 22-27

Electrical Parameters Estimation of Solar Photovoltaic Module

Mustapha B. U.; MusaM. K. Dikwaand M. Abbagana¹………………………………                       28-37

Determination of the Rheological Properties of Drilling Fluid From

Locally Sourced Clay from Various Geographical Areas

Ajugwe .C, Oloro. J and Akpotu. D.………………………………………………………………                      38-49

Electric Bill Payments by Unmetered Consumers

P.A. Kuale and S.O. Otuagoma ………………………………………………………………….                     50-60

Differential Evolution Based Optimal Placement and Sizing of Two

Distributed Generators in a Power Distribution System

M. Abbagana, G. A. Bakare, I. Mustaph, B.U.Musa………………………………………..                61-70

Seismic Refraction and Electrical Resistivity Investigation for Groundwater

at Fatu Maimasa along Kogin Gabas Road Nasarawa L.G.A. Nasarawa State

Mohammed B.I.; Yakubu, W.L and Annu U.J………………………….………………………               71-78

Resistivity Investigation of Subsurface Structures along Sarkin Pawa-

Mangoro Road Pavement, Niger state, Nigeria

Jatto S. S., Sule P. O. and Ahmed A. L ……………………………………………………..  79-90

RESISTIVITY INVESTIGATION OF SUBSURFACE STRUCTURES ALONG SARKIN PAWA-MANGORO ROAD PAVEMENT, NIGER STATE, NIGERIA

*Jatto S. S., **Sule P. O. and Ahmed A. L.

Department of Physics

Ahmadu Bello University, Zaria, Nigeria

Email: ssjatto@yahoo.com

ABSTRACT

Geophysical investigations involving the Schlumberger vertical electrical sounding (VES) and Wenner horizontal electrical profiling have been carried out along some stable and unstable sections of the Sarkin-Pawa-Mangoro road in Niger State. This is to investigate the geological factors responsible for the incessant pavement failure within the area. The vertical electrical soundings have been carried out along two traverses P_A and P_B measuring 1350 metres long respectively, one on each side of the road. 28 VES stations at a station separation of 50 metres are on each traverse. The horizontal electrical profiling was carried out with an electrode separation of 10 metres on traverse P_A over a distance of 1150 metres. The geoelectric/geologic sections along the stable segments of the road show generally resistive topsoil with resistivity values ranging from 130-600 Ωm. Beneath the unstable segments, the geoelectric sections show low resistivity clay topsoil (20-120 Ωm), water absorbing substratum, and near-surface water table. The electrical profiling indicates conductive zones beneath the unstable sections. The high and low values of the apparent resistivity data of the electrical profiling may be an indication of the natural variation in the composition of the subsurface or the presence of linear features such as fracture, buried ditch/stream channel or shear zones. The unstable sections which correspond to pavement failure can hence be delineated using geophysical investigations and thus enabling necessary remedial actions to be taken when constructing a new road.

Key words: Vertical electrical sounding, Mangoro, Geoelectric Section, Resistivity, Pavement failure, electrical profiling.

SEISMIC REFRACTION AND ELECTRICAL RESISTIVITY INVESTIGATION FOR GROUNDWATER AT FATU MAIMASA ALONG KOGIN GABAS ROAD NASARAWA L.G.A. NASARAWA STATE

¹Mohammed B.I.; ²Yakubu, W.L and ²Annu U.J.

¹Department of Agricultural Engineering and ²Department of Agricultural Technology

Nasarawa State College of Agriculture, Lafia

Email: mbabaibraheem@yahoo.com

ABSTRACT

A geophysical survey involving vertical Electrical sounding (VES) and seismic refraction was carried out in Salri Integrated Farm along Kogin Gabas area of Nasarawa Local Government Area. A 12- channel ABEM Teraloc MKVI seismograph and ABEM Terameter model SAS 3OOC were used with their accessories in the surveys. The results of the survey showed that the depths to Basement rock rang from 24m to 47m at different places .The VES investigation further revealed that the over burden (regolith) generally consists of lateritic top soil coarse or gravelly sand, clayey sand or finely weather Basement rock and fractured Basement all overlying the fresh crystalline Basement rock. The lithologic section obtained from nearby boreholes showed good correlation with the interpreted geoelectric sections. The results of this study suggest that the area studied has good potential for ground water development or borehole programme.

DISTRIBUTED GENERATORS IN A POWER DISTRIBUTION SYSTEM

M. Abbagana^1*, G. A. Bakare², I. Mustapha¹,,B.U.Musa¹

¹Department of Electrical and Electronics Engineering, University of Maiduguri, Nigeria

²Electrical Engineering Programme, Abubakar Tafawa Balewa University, Bauchi Nigeria.

E-mail: moduabbagana@yahoo.com,   bakare_03@yahoo.com, mustib@unimaid.edu.ng, musa_bu@yahoo.com

ABSTRACT

Distributed and disperse generation of electricity have been used to address economical and environmental challenges associated with centralized generation of electricity. This paper aims to minimize the power losses and improve the voltage profile of power distribution system by determining the optimal location and size of two Distributed Generation (DG) units. Differential Evolution (DE) technique is used for optimizing the formulated problem. Performance of the technique is tested on IEEE 33 bus radial distribution system consisting of 32 sections and six different scenarios were created by varying the DE parameters. MATPOWER and MATLAB software were used for the simulation. The results show that proper placement and size of DG units can have a significant impact on system loss reduction and voltage profile improvement. On the other hand, improper choice of size would lead to higher losses.

Keywords: Differential Evolution, Distributed Generation, Loses, Optimization, Voltage, Nodes

P.A. Kuale and S.O. Otuagoma

Department of Mechanical Engineering Technology 

Rufus Giwa Polytechnic, Owo, Ondo State

SUMMARY

Many electric energy consumers’ premises are not metered. Accordingly estimated bills are sent to them. In some cases, meters are not read, but bills are still sent to consumers. This study showed that the estimated bills by PHCN sent to consumers, without meters is on the high side. It is very necessary for consumers to be billed for the actual energy consumed. That PHCN should ensure that all consumer premises are metered and accordingly when meters are not available PHCN should examine our work and do their own study and come to accurate figures for billing consumers.

DETERMINATION OF THE RHEOLOGICAL PROPERTIES OF DRILLING FLUID FROM LOCALLY SOURCED CLAY FROM VARIOUS GEOGRAPHICAL AREAS

Ajugwe  C; Oloro. J  and Akpotu. D.

Department of Petroleum Engineering

Delta State University, Oleh Campus

E-mail: joloroeng@yahoo.com

ABSTRACT

The rheological formulation of our locally sourced bentonite clay in substitute for the imported foreign bentonite clay was carried out by the comparative analysis of the parameters of the local mud with the stipulated API standard values to ascertain the level of compliance in drilling operation. The local muds P^H values responded positively on beneficiation with 1.0g of potash, the modification raised the muds P^H values to fall within the standard range of 9.5 to 12.5. The viscosity of the local muds was seen to be slightly below the standard requirement of 30cp, but appreciated favorably to the standard requirement when beneficiated with 1.0g of drispac. On beneficiating the foreign aqua gel bentonite muds, with the same quantity of additives used on other mud samples, there was an excessive abnormal increase in its viscosity for instance the viscosity of 17.5g of the foreign mud was drastically raised from 17.1cp to 210.5cp at 600 dial reading. It was obvious that most of the prepared local  mud samples parameters such as the sand percentage composition, power law index, density, marsh funnel viscosity, etc met the minimum required specifications,  while other few parameters such as the theological properties, needed some additive treatment for favorable comparison with the foreign clay mud properties. Therefore, the utilization of these clays for any industrial application will pose no harm to surface and surface facilities and will in no turn represent a value added to the Nigeria economy by the total prevention of the important of high quality activated foreign bentonite clay. Tests and analysis were carried out on Local Clay samples obtained from a town in delta state, imo state and the foreign commercial bentonite. This research is to evaluate the performance of the Local clay samples for drilling operations in Nigeria. The rheological and the thixotropic properties as well as other parameters of the Local clay mud was seen to have improved, but however, when beneficiated with chemical additives of different concentrations, there was an increase in the overall parameters of the Local mud samples, making them ideal for any industrial application as their parameters met with the stipulated standard specifications of API, OCDA.

ELECTRICAL PARAMETERS ESTIMATION OF SOLAR PHOTOVOLTAIC MODULE

¹ I. Mustapha; B. U. Musa¹; M. K. Dikwa² and M. Abbagana¹

¹Department of Electrical and Electronics Engineering, University of Maiduguri, Nigeria

 ²Department of Computer Engineering, University of Maiduguri, Nigeria

E-mail:ibrahimmassa@yahoo.com, musa_bu@yahoo.com, mkdikwa@gmail.com, moduabbagana@yahoo.com

ABSTRACT

Environmental Weather conditions such as ambient temperature and solar irradiance have significant impact on predicting I-V and P-V characteristics of solar PV modules. Electrical parameters of solar PV modules at site of installation differ from those provided by the manufacturer due to variation in environmental conditions such as solar irradiance and ambient temperature. This paper estimates electrical parameters of a monocrystalline solar photovoltaic module (SW 250) with respect to Maiduguri weather conditions. A simple one-diode mathematical model was implemented using MATLAB script which predicts the I-V and P-V characteristics of the solar PV module based on Local Operating Conditions (LOC) i.e Maiduguri environmental weather conditions. Simulation results confirmed that electrical parameters at LOC differ slightly with that provided by the manufacturer at Standard Test Conditions (STC) and Nominal Operating Cell Temperatures (NOCT). The results show that the  short circuit current and the peak current at LOC are 8.7% and 9.5% less than that at NOCT respectively, while the open circuit voltage and the peak voltage at LOC differed by 15% and 7.5% to that at NOCT respectively. The maximum power at LOC is 17.5% less than that provided by the manufacturer at NOCT. Thus the photovoltaic module exhibited good performance in the region under study.

Keywords- Photovoltaic module, short circuit current, irradiance, temperature, open circuit voltage